When did you last look at an election poll tracker? Today, probably. Maybe yesterday. How much time did you spend considering how that information flows from the pollsters through data centers via scripted pages and eventually to your browser? You probably didn't give it a moment's thought.

But stop for a moment. Aren't these live trackers a miracle of technology, a desire to share information, and human ingenuity?

To fully appreciate the poll-trackers of today, let's take a look back at how we used to share election data 100-plus years ago. Read on, and then, when you next fire up a live poll tracker, take a moment to ponder the miracle of data and design that has created it.

1864

Scott Klein, ProPublica

Election results communication, 1864

Before charts, before electricity, people still wanted the information. This they managed by watching someone hand-writing the results on boards, lit by a bonfire beneath the windows. Above we're looking at results from the Abraham Lincoln election of 1864 as seen in an issue of Frank Leslie's Illustrated Newspaper.

1896

At the end of the 19th century, data was growing. People were presenting data in tables (indeed, the Tab key was added to typewriters around this time), but journalists realized that information needed to be shared quickly, in an easily digestible way. The choropleth map arrived in 1896, on the front cover of The New York Times.

Scott Klein, ProPublica

Front page of The New York Times, 1896

The figure above shows the NYT the day after the election. This was astonishing: How had the paper created a results chart so quickly? Simple -- it didn't use final results data! You can see the differences below.

Scott Klein, ProPublica

New York Times election map compared to final results

The NYT did at least call the result correctly (victory to McKinley), but this exposed one of the tensions in sharing data: balancing the race to publish a result with the need for accuracy.

1900-1930s

Thomas Edison's Searchlight

It's this period which I find the most fascinating. Searchlights were a hot new technology in the early 20th century, and they could be used to show data. How? By pointing them in different directions according to the results. Below are some images of how the NYT would use its searchlights to convey information.

Scott Klein, ProPublica

New York Times headquarters and data-driven searchlights

As well as searchlights, early projection methods were being used with projectors and slides. In a time before TV, and even radio, people were happy to travel to the city or town center to watch information projected from newspapers' buildings. This continued well into the 1930s; on the night of the 1936 election, hundreds of thousands of people crowded Times Square in New York.

Even though the practice of sharing information this way was commonly used, it was not always done well. Willard Brinton, in his 1914 book "Graphical Methods for Presenting Facts," wrote that "thus far the lantern slides give only very brief scrawled sentences."

This was a problem because "a person coming out into the street after an evening in the theater has no way of knowing the import of the various statements which may have been thrown on the screen earlier in the evening." Brinton also recognized the importance of not just showing the election data in a map, despite the allure of U.S. geography:

2016

Fast-forward to today. Now election trackers are instant and everywhere. The choropleth map has persisted (despite its flaws), but there are many new and innovative approaches to data visualization in each election cycle.

This is a section from Mike Cisneros' prediction model

In another 100 years, when we look back at 2016, which innovations of today do you think we will fondly remember?

Andy Cotgreave (@acotgreave helps people see and understand their data. He has been with Tableau in various roles since 2011 ranging from product consultant to product marketing to his current role as Senior Technical Evangelist.